The present invention relates to a fluid transferring or compressing machine, such as a turbo-pump, a turbo-compressor or the like.
xe2x80x9cKagen-kyokai-kohza 1. Pumpxe2x80x9d published from Karyoku-genshiryoku-hatsuden-gijutsu-kyokai on April, 1988 discloses on page 24 thereof that diffuser vanes, diffuser side plates and return flow vanes are fixed by welding to a laminated inner casing fixed to an outer casing in a barrel casing type turbopump.
JP-A-60-151530 discloses that rotor urging forces by fluidal pressures discharged from respective impeller stages of a rotating rotor balance each other to decrease a vibration of the fluidal machine.
It is well known that a pump is surrounded by a soundproof cover, or a lead plate surrounds a pipe or coupling-cover.
An object of the present invention is to provide a fluidal machine in which a vibration generated at a front end of a diffuser vane receiving a fluid urged by a rotating impeller is prevented or restrained from being transmitted to an outer casing contacting the atmosphere and/or to a pipe or an impeller driver motor through the outer casing.
According to the present invention, in a fluidal machine with an impeller rotating to urge a fluid radially outwardly by a centrifugal force, a vane guiding the fluid discharged from the impeller, a vane member which includes a front end of the vane facing to the impeller so that the fluid discharged from the impeller strikes against the front end and which is prevented from contacting the atmosphere, and a casing surrounding the vane member and contacting the atmosphere, at least one of the vane member and the casing has an elastically deformable portion (a compressed deformation surface spot and/or bent deformation portion of a pin, a compressed deformation surface spot of a hole receiving the pin, compressed deformation surface spots and/or bent deformation portions of joint points spaced apart from each other in a circumferential direction between the vane member and the casing, a compressed deformation part and/or bent deformation part and/or shear deformation part of an elastic member between the vane member and the casing) connected to another one of the vane member and the casing without a rigid and/or substantially monolithic connection between the vane member and casing so that a connecting rigidity between the vane member and the casing in at least one of an impeller axial direction, an impeller radial direction and an impeller circumferential direction is decreased. It is preferable that modulus of longitudinal and/or transverse elasticity or spring constant of the elastic member is less than that of the vane member and the casing. The joint points may be formed by spot welding between the vane member and the casing.
In the present invention, since the connecting rigidity (vibration transfer function) between the vane member and casing discrete from or independent of each other in at least one of an impeller axial direction, an impeller radial direction and an impeller circumferential direction is decreased by the elastically deformable portion, a vibrating deformation magnitude of the casing is kept smaller than that of the vane member so that a vibration of the vane member with the front end of the vane caused by the fluidal force discharged from the impeller is prevented or restrained from being transmitted to the casing.
In the prior art, since the vane member and the casing are fixed to each other monolithically and rigidly by a circumferentially continuous welding or a compression with screws, the elastically deformable portion is not formed between the vane member and the casing and the connecting rigidity therebetween is not decreased, that is, the vibrating deformation magnitude of the casing is substantially equal to that of the vane member and a transfer efficiency of the vibration from the vane member to the casing is significantly high.
It is preferable for improving a vibration isolation between the vane member and the casing (or an inner casing of the casing described below) that a deformation of the vane member in the impeller axial or radial direction is prevented from being restrained by the casing, that is, a clearance in the impeller axial and/or radial direction is formed between the vane member and the casing (or the inner casing of the casing) so that the vane member is slightly movable in the impeller axial and/or radial direction, and/or a spring member whose modulus of elasticity or spring constant is smaller than modulus of elasticity or spring constant of the vane member and/or the casing is arranged in the clearance to restrain or decrease a compression force in the impeller axial and/or radial direction applied to the vane member.
Substantially only the elastically deformable portion may prevent at least one of a radially outward deformation and a circumferential movement of the vane member caused by the fluid force discharged from the impeller so that the vibration of the vane member is transmitted to the casing through substantially only the elastically deformable portion.
It is preferable that the vane member is slightly movable relative to the casing in the impeller axial direction at least in a part of a temperature range of the fluidal machine during operation, and/or the vane member is slightly movable relative to the casing in at least one of the impeller radial direction and the impeller circumferential direction by the fluidal force discharged from the impeller so that the elastically deformable portion approaches the another one of the vane member and the casing when the elastically deformable portion is apart from the another one of the vane member and the casing.
It is preferable for accelerating a vibration absorption and preventing a fretting corrosion between the vane member and the casing that the vane member and the casing have respective surfaces through which the vane member and the casing contact each other, and a contacting pressure between the surfaces is limited to such a degree that the fluid exists between the surfaces.
According to the present invention, in a fluidal machine with an impeller rotating to urge a fluid radially outwardly by a centrifugal force, a vane guiding the fluid discharged from the impeller, a vane member which includes a front end of the vane facing to the impeller so that the fluid discharged from the impeller strikes against the front end and which is prevented from contacting the atmosphere, and a casing surrounding the vane member and contacting the atmosphere, the vane member is discrete from the casing without a rigid and/or substantially monolithic connection there between, and a deformation of the vane member in at least one of an impeller axial direction and the impeller radial direction is prevented from being restrained by the casing.
In the present invention, since the deformation of the vane member in the at least one of an impeller axial direction and the impeller radial direction is prevented from being restrained by the casing, the deformation of the vane member is independent of that of the casing so that the vibration isolation between the vane member and the casing is formed.
In a fluidal machine with an impeller rotating to urge a fluid radially outwardly by a centrifugal force, a vane guiding the fluid discharged from the impeller, a vane member which includes a front end of the vane facing to the impeller so that the fluid discharged from the impeller strikes against the front end and which is prevented from contacting the atmosphere, and a casing surrounding the vane member and contacting the atmosphere, the vane member is discrete from the casing, and at least one of a radial movement and a circumferential movement of the vane member caused by the fluid force discharged from the impeller is prevented by the casing through substantially only one axial side of the vane member without a substantially monolithic and/or rigid connection between the one axial side of the vane member and the casing.
In the present invention, since at least one of a radial movement and a circumferential movement of the vane member caused by the fluid force discharged from the impeller is prevented by the casing through substantially only the one axial side of the vane member, a contacting area or connecting cross section between the vane member and the casing is kept small to decrease or throttle a vibration propagation from the vane member to the casing.
In the prior art, since the vane member and the casing are fixed monolithically and rigidly to each other through both axial sides of the vane member by the circumferentially continuous welding or compressing with the screws, the contacting area between the vane member and the casing is large so that a vibration propagation efficiency from the vane member to the casing is high.
The elastic member more softly deformable in comparison with the vane member and/or the casing in at least one of the impeller radial direction, the impeller axial direction and the impeller circumferential direction may be arranged between the vane member and the casing.
According to the present invention, in a fluidal machine with an impeller rotating to urge a fluid radially outwardly by a centrifugal force, a vane guiding the fluid discharged from the impeller, a vane member which includes a front end of the vane facing to the impeller so that the fluid discharged from the impeller strikes against the front end and which is prevented from contacting the atmosphere, and a casing surrounding the vane member and contacting the atmosphere, the vane member is discrete from the casing, and the casing has an outer casing contacting the atmosphere and an inner casing which is surrounded by the outer casing, is prevented from contacting the atmosphere, is arranged between the vane member and the outer casing and contacts the vane member, the inner casing is discrete from the outer casing without a rigid and/or substantially monolithic connection therebetween, and the vane member is discrete from the inner casing without a rigid and/or substantially monolithic connection therebetween.
In the present invention, since the inner casing contacting the vane member is discrete from the outer casing contacting the atmosphere and the vane member is discrete from the inner casing, a contact without monolithic and rigid connection between the inner casing and the vane member is formed between the vane member and the atmosphere so that the inner casing is isolated from the vibration of the vane member by the contact without monolithic and rigid connection.
An axial and/or radial deformation of the vane member may be substantially prevented from being restrained by the inner casing.
The substantially monolithic connection means non-spot continuous welding connection, tight and interference fitting, strong pressing against each other, or the like.